Firstly, I wanted to use arduino to find a way to trigger light sequences with my Launchpad, which is a usb-MIDI controller. I'm fairly sure it's possible, but I wanted to start by making something a bit simpler, as the only electronics project I've ever done was a toothbrush head with a vibrator attached to it.

I want to make sound activated lights, but have them be activated in different ways. I don't think I'd need arduino for this, as I've been told it can be done without a processor. I want to make:-Lights that fade in and out depending on which frequency they pick up-And lights that simply respond to loudness

If you want to pick up frequencies out of an audio signal, I THINK you would be looking at Fast Fourier Transforms (FFT). It is pretty complicated to understand, but I recommend reading about it. Basically you take a sample of audio, then it outputs some numbers that you can translate into frequency ranges. Although, this is just software, so if you wanted to detect a certain number of frequencies at specific frequencies, you can build those too through hardware. Check this video out, https://www.youtube.com/watch?v=3sf6lq6NcJU

If you can't write your program in plain english where anyone could understand it then you have no hope of writing code for it. -Delta_G